All-solid waste geopolymer grouting material and preparation method thereof

Abstract

The invention provides an all-solid waste geopolymer grouting material and a preparation method thereof, and relates to the technical field of solid waste resource utilization and geopolymer grouting material preparation. The all-solid waste geopolymer grouting material comprises the following raw materials in parts by weight: 100-200 parts of an all-solid waste mixture, 40-50 parts of an alkaline activator, 0.1-0.5 part of an early strength agent, 0.5-1 part of a water reducing agent, 3-7 parts of a modifier and 70-90 parts of water, the all-solid waste material comprises slag powder, steel slag powder, phosphogypsum and fly ash; the modifying agent is prepared from aluminum dihydrogen phosphate, vinyl triacetoxysilane and ethylenediamine terminated polyethyleneimine. The all-solid waste geopolymer grouting material provided by the invention has the characteristics of good working performance, high early strength, micro-expansibility and the like.

Description

Technical Field

[0001] The present invention relates to the technical fields of solid waste resource utilization and preparation of geopolymer grouting materials, and particularly to an all-solid-waste ultra-high performance geopolymer grouting material and a preparation method thereof. Background Art

[0002] During the long-term use of roads, under the influence of various factors such as geological environment and vehicles, various diseases will occur, with cracks, holes, depressions, and voids being the most serious, and ultimately the bearing capacity of the road will decline or even subside. The method of milling and resurfacing the base layer has problems such as long construction time, complex construction technology, high comprehensive cost, and high carbon emissions. Cement grouting materials are commonly used materials for road grouting treatment at present, but cement grouting materials have problems such as long setting time, poor stability, high bleeding rate, and large shrinkage. Moreover, the proportion of cement in cement grouting materials is relatively high, resulting in high energy consumption, and the production of cement will cause environmental pollution. Geopolymer grouting materials are a new type of foundation reinforcement material formed by the depolymerization-repolymerization reaction of various solid waste powders under the action of activators. They have excellent mechanical properties, simple construction technology, low comprehensive cost, and can also solve the problems of land occupation and environmental pollution caused by solid waste stacking, and are expected to replace high-energy-consuming grouting materials such as cement grouting materials.

[0003] However, for grouting in weak areas with poor injectability such as voids and holes in road subgrades or cracks in the base layer, higher technical requirements are put forward for road geopolymer grouting materials. The grouting materials are required to have higher fluidity to achieve grouting, excellent reinforcement effects, and can react and solidify at normal temperature to form higher strength. At present, when using existing geopolymer grouting materials to grout areas such as voids and holes or cracks in roads, there are still problems with poor working performance and mechanical properties, which limits the application of geopolymer grouting materials in road reinforcement and strengthening projects.

[0004] Therefore, the present invention aims to make full use of industrial solid waste materials and develop an all-solid-waste geopolymer grouting material. Through the synergistic reaction among industrial solid wastes such as fly ash, slag, steel slag, and phosphogypsum, combined with the accelerating curing effect of polymer, a new type of green and environmentally friendly polymer material is further reorganized and combined, which can be used for base layer reinforcement, soft soil reinforcement, etc. Summary of the Invention

[0005] Aiming at the deficiencies of the prior art, the present invention provides an all-solid-waste geopolymer grouting material and a preparation method thereof. The all-solid-waste geopolymer grouting material has the characteristics of good working performance, high early strength, and slight expansion.

[0006] To achieve the above objectives, the present invention is realized through the following technical solutions:

[0007] A fully solid waste geopolymer grouting material, comprising raw materials in the following parts by weight: 100-200 parts of fully solid waste mixture, 40-50 parts of alkaline activator, 0.1-0.5 part of early strength agent, 0.5-1 part of water reducing agent, 3-7 parts of modifier, and 70-90 parts of water; the fully solid waste materials include slag powder, steel slag powder, phosphogypsum, and fly ash; the modifier includes aluminum dihydrogen phosphate, vinyltriacetoxysilane, and ethylenediamine-terminated polyethyleneimine.

[0008] The fully solid waste geopolymer grouting material of the present invention activates multi-component solid waste by using the alkali activation principle, and then uses a specific modifier to improve the three-dimensional structure of the geopolymer grouting material at the microscopic level, so that the synergistic effect of the four-component solid waste materials of slag powder, steel slag powder, phosphogypsum, and fly ash is enhanced, the particles are more closely combined with each other, and the microscopic distribution is more orderly, generating a large amount of hydration products such as calcium silicate hydrate and calcium aluminosilicate hydrate, so that the prepared fully solid waste geopolymer grouting material has a shorter setting time, better fluidity, and higher early strength. Among them, aluminum dihydrogen phosphate will release phosphate ions and aluminum ions during the dissolution process, and will undergo ion exchange with the alkaline substances on the surface of the activated fully solid waste, promoting the dispersion of particles. In addition, aluminum dihydrogen phosphate can react with the activated solid waste materials to generate phosphate substances, which are filled into the pore structure of the grouting material, improving the early strength and stability of the grouting material; vinyltriacetoxysilane is easy to hydrolyze, and the acetic acid released by hydrolysis and the generated silanol can generate calcium silicate substances and fill into the pores of the grouting material. Silanol itself will also undergo a polycondensation reaction to form a three-dimensional network structure of polysiloxane, overall enhancing the integrity and stability of the grouting material structure; ethylenediamine-terminated polyethyleneimine contains a large number of amino groups on the molecular chain, which can adsorb on the surface of solid waste particles, making the material dispersion more uniform, and the amino groups can react with metal ions to form stable complexes. During the hydration process, ethylenediamine-terminated polyethyleneimine fully exerts a bridging effect to affect the crystallization process and growth direction of hydration products, guiding precipitation to form at specific positions, making the microscopic structure of the grouting material more orderly. In addition, it can promote the more in-depth and uniform combination reaction of vinyltriacetoxysilane and aluminum hydrogen phosphate with the active surface of solid waste particles, making the particles more closely combined; the synergistic effect of vinyltriacetoxysilane, aluminum hydrogen phosphate, and ethylenediamine-terminated polyethyleneimine enables the body to achieve a balance between fluidity and adhesiveness, improving the fluidity and plasticity of the grouting material, better connecting solid waste particles, promoting the early hydration of the grouting material, and the generated products are intertwined with each other, enhancing the structural density, so that the early strength and later strength of the grouting material are significantly improved.

[0009] Preferably, the mass ratio of aluminum dihydrogen phosphate, vinyltriacetoxysilane, and ethylenediamine-terminated polyethyleneimine is (2-3):(0.5-2):1. Further preferably, the mass ratio of aluminum dihydrogen phosphate, vinyltriacetoxysilane, and ethylenediamine-terminated polyethyleneimine is 2.5:1.5:1.

[0010] Preferably, the number average molecular weight of the ethylenediamine-terminated polyethyleneimine is 600 - 800.

[0011] Preferably, the raw materials of the all-solid waste mixture include slag powder, steel slag powder, phosphogypsum and fly ash, and the mass ratio of the slag powder, steel slag powder, phosphogypsum and fly ash is (20 - 50):(25 - 45):(30 - 60):(5 - 30).

[0012] Preferably, the alkaline activator is at least one of sodium hydroxide, potassium hydroxide, water glass, and sodium carbonate.

[0013] Preferably, the early strength agent is a mixture of sodium thiosulfate and triisopropanolamine with a mass ratio of 1:(0.2 - 0.5), and the water reducing agent is a polycarboxylate water reducing agent.

[0014] The present invention also discloses a preparation method of an all-solid waste geopolymer grouting material described in any one of the above, including the following steps: S1. Mix the slag powder, steel slag powder, phosphogypsum, and fly ash evenly to obtain an all-solid waste mixture; S2. Activate the all-solid waste mixture, alkaline activator and 1 / 3 of water; S3. Add a certain proportion of early strength agent, water reducing agent, modifier and the remaining water to the mixture obtained in step S2 and mix evenly to obtain an all-solid waste geopolymer grouting material.

[0015] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0016] (1) The geopolymer of the present invention makes full use of industrial solid waste, has a high utilization rate of solid waste and a large consumption volume, realizing taking from waste and using for roads.

[0017] (2) The geopolymer of the present invention is environmentally friendly. The raw materials of the geopolymer are all solid wastes. Using vinyltriacetoxysilane, aluminum hydrogen phosphate and ethylenediamine-terminated polyethyleneimine in specific proportions as modifiers and reacting with the all-solid waste materials after alkali activation through geopolymerization, synergistically achieving a good balance between the adhesiveness and fluidity of the grouting material, enhancing the dispersibility of solid waste particles and the bonding force between particles. The silicon in the solid waste has a coordination isomorphism effect on aluminum, enabling the formation of a complex three-dimensional network structure in the matrix, promoting the generation of a large amount of C(N)-A-S-H amorphous gel substances inside the geopolymer, forming a dense gel structure, improving the early strength and stability of the grouting material, and thus enhancing the comprehensive road performance of the grouting material.

[0018] (3) The geopolymer of the present invention has the following characteristics: quick setting and early strength, slight expansion, economic durability, green and low-carbon. The geopolymer of the present invention has a wide range of applicability, and the setting time of the geopolymer can be controlled. It is not only applicable to the trenchless reinforcement of the existing highway subgrade, but also can achieve rapid opening to traffic, ensure smooth traffic, and reduce investment; it can also be used for the reinforcement of the old road subgrade and soft soil reinforcement in the reconstruction and expansion of highways. Description of the Drawings

[0019] Appendix Figure 1 The deflection detection and evaluation curve before and after grouting in the embodiment of the present invention;

[0020] Appendix Figure 2 The comparison diagram of the repair effects of the all-solid waste geopolymer grouting material on the loose subgrade and subgrade cracks in the embodiment of the present invention. Detailed Embodiments

[0021] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0022] An all-solid waste geopolymer grouting material includes the following raw materials in parts by weight: 100-200 parts of all-solid waste mixture, 40-50 parts of alkaline activator, 0.1-0.5 part of early strength agent, 0.5-1 part of water reducing agent, 3-7 parts of modifier, and 70-90 parts of water; the all-solid waste material includes slag powder, steel slag powder, phosphogypsum, and fly ash, and the mass ratio of the slag powder, steel slag powder, phosphogypsum, and fly ash is (20-50):(25-45):(30-60):(5-30); the modifier includes aluminum dihydrogen phosphate, vinyltriacetoxysilane, and ethylenediamine-terminated polyethyleneimine.

[0023] In some examples, the mass ratio of the aluminum dihydrogen phosphate, vinyltriacetoxysilane, and ethylenediamine-terminated polyethyleneimine is (2-3):(0.5-2):1.

[0024] In some examples, the number average molecular weight of the ethylenediamine-terminated polyethyleneimine is 600-800.

[0025] In the following examples and comparative examples, unless otherwise specified, the main chemical component of the phosphogypsum is that the CaO content is 38.0%, SiO 2 content is 8.3%, 500m 2 / kg; the slag powder is S95 granulated blast furnace slag, and the specific surface area is 450m 2 / kg; The steel slag powder is converter steel slag powder, with a material fineness of 500 mesh, a CaO content of 48.3%, an alkalinity of 3.1, and a specific surface area of 500 m 2 / kg; The fly ash is Class F fly ash of Grade 1, with a fineness of 500 mesh; The alkaline activator is sodium hydroxide; The early strength agent is a mixture of sodium thiosulfate and triisopropanolamine with a mass ratio of 1:0.3, the water reducing agent is a polycarboxylate water reducing agent, and the number average molecular weight of the ethylene diamine terminated polyethyleneimine is 600.

[0026] Example 1

[0027] A fully solid waste geopolymer grouting material, comprising the following raw materials in parts by weight: 100 parts of fully solid waste mixture, 40 parts of alkaline activator, 0.3 parts of early strength agent, 0.5 parts of water reducing agent, 5 parts of modifier, and 70 parts of water; The fully solid waste materials include 35 parts of slag powder, 30 parts of steel slag powder, 30 parts of phosphogypsum, and 5 parts of fly ash; The modifier includes aluminum dihydrogen phosphate, vinyltriacetoxysilane, and ethylene diamine terminated polyethyleneimine with a mass ratio of 2:2:1.

[0028] The preparation method of the above fully solid waste geopolymer grouting material includes the steps: S1. Mix the slag powder, steel slag powder, phosphogypsum, and fly ash to obtain a fully solid waste mixture; S2. Mix and activate the fully solid waste mixture, alkaline activator, and 1 / 3 of the water; S3. Add the early strength agent, water reducing agent, modifier, and the remaining water to the mixture in step S2 in proportion and mix evenly to obtain the fully solid waste geopolymer grouting material.

[0029] Example 2

[0030] A fully solid waste geopolymer grouting material, comprising the following raw materials in parts by weight: 150 parts of fully solid waste mixture, 45 parts of alkaline activator, 0.3 parts of early strength agent, 0.8 parts of water reducing agent, 3 parts of modifier, and 80 parts of water; The fully solid waste materials include 50 parts of slag powder, 25 parts of steel slag powder, 50 parts of phosphogypsum, and 25 parts of fly ash; The modifier includes aluminum dihydrogen phosphate, vinyltriacetoxysilane, and ethylene diamine terminated polyethyleneimine with a mass ratio of 2.5:1.5:1. The preparation method is the same as that of Example 1.

[0031] Example 3

[0032] A fully solid waste geopolymer grouting material, comprising the following raw materials in parts by weight: 200 parts of fully solid waste mixture, 50 parts of alkaline activator, 0.5 parts of early strength agent, 1 part of water reducing agent, 7 parts of modifier, and 90 parts of water; The fully solid waste materials include 40 parts of slag powder, 50 parts of steel slag powder, 90 parts of phosphogypsum, and 20 parts of fly ash; The modifier includes aluminum dihydrogen phosphate, vinyltriacetoxysilane, and ethylene diamine terminated polyethyleneimine with a mass ratio of 3:1:1. The preparation method is the same as that of Example 1.

[0033] Comparative Example 1

[0034] The 42.5 ordinary Portland cement grouting material was used as a comparison, and the water-cement ratio was 0.7.

[0035] Comparative Example 2

[0036] The geopolymer grouting material was basically the same as that in Example 2, except that: the modifier was vinyltriacetoxysilane and ethylene diamine-terminated polyethyleneimine with a mass ratio of 1.5:1.

[0037] Comparative Example 3

[0038] The geopolymer grouting material was basically the same as that in Example 2, except that: the modifier was aluminum dihydrogen phosphate, vinyltriacetoxysilane, and polyethyleneimine with a mass ratio of 2.5:1.5:1.

[0039] Comparative Example 4

[0040] The geopolymer grouting material was basically the same as that in Example 2, except that: the modifier was aluminum dihydrogen phosphate, vinyltriethoxysilane, and ethylene diamine-terminated polyethyleneimine with a mass ratio of 2.5:1.5:1.

[0041] The fluidity, setting time, and mechanical properties of the grouting materials in Examples 1-3 and Comparative Examples 1-4 were tested. The fluidity test used a flow cone to measure the fluidity of the slurry, and the time required for 1725 mL ± 5 mL of the grouting material to completely flow out was used to characterize it. The less time used, the better the fluidity of the grouting material. The mechanical property test referred to the "Test Regulations for Cement and Cement Concrete in Highway Engineering" (JTG 3420-2020) and the "Technical Specification for Application of Cement-based Grouting Materials" (GB / T 50448-2015). Specimens with a size of 40 mm × 40 mm × 160 mm were molded using a triple mold and subjected to a compressive test.

[0042]

[0043] As can be seen from the above table, compared with Example 1, Cement grouting material was used in Comparative Example 1, diammonium hydrogen phosphate was missing in Comparative Example 2, polyethyleneimine was used to equivalently replace ethylene diamine-terminated polyethyleneimine in Comparative Example 3, and vinyltriethoxysilane was used to replace vinyltriacetoxysilane in Comparative Example 4. The working performance and mechanical properties of the obtained grouting material were much lower than those of the grouting material in the embodiment of the present invention. This is mainly because the present invention activates the multi-component solid waste materials by using the alkali activation principle, and the vinyltriacetoxysilane, diammonium hydrogen phosphate and ethylene diamine-terminated polyethyleneimine in specific proportions can synergistically achieve a good balance between the adhesiveness and fluidity of the grouting material, enhance the dispersibility of the solid waste particles and the binding force between the particles, form a complex three-dimensional network structure in the body, promote the generation of a large amount of amorphous C(N)-A-S-H gel substances inside the geopolymer, form a dense gel structure, improve the early strength and stability of the grouting material, and thus improve the comprehensive road performance of the grouting material.

[0044] Application Example

[0045] The full-solid waste geopolymer grouting material of the present invention was used to reinforce the base course of a certain highway, and the deflection value decreased by 30% before and after grouting. See the appendix Figure 1 In addition, the inventor also used the full-solid waste geopolymer grouting material to repair the loose base course and the cracks in the base course. For the specific repair effect, see the appendix Figure 2 .

[0046] All in all, the geopolymer grouting material in the embodiment of the present invention has significant advantages compared with the traditional maintenance method: Construction time: The traditional cement maintenance method has a long maintenance time, slow strength formation, and a great impact on traffic closure; The geopolymer of the present invention has wide applicability, the setting time of the geopolymer can be controlled, it has quick setting and early strength, slight expansion, economic durability, and is green and low-carbon. It is not only suitable for the trenchless reinforcement of the existing highway base course, but also can be used for the reinforcement of the old road base course and soft soil reinforcement in the reconstruction and expansion of highways. Environmental protection: Compared with cement grouting, the carbon emission can be reduced by 81% per kilometer.

[0047] Although the embodiments of the present invention have been shown and described, those of ordinary skill in the art can understand that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principle and spirit of the present invention. The scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A full solid waste geopolymer grouting material, characterized in that: The method comprises the following raw materials in parts by weight: 100-200 parts of all-solid waste mixture, 40-50 parts of alkaline activator, 0.1-0.5 parts of early strength agent, 0.5-1 parts of water reducer, 3-7 parts of modifier and 70-90 parts of water; the all-solid waste materials comprise slag powder, steel slag powder, phosphogypsum and fly ash; the modifier is composed of aluminum dihydrogen phosphate, vinyl triacetoxysilane and polyethyleneimine terminated with ethylenediamine.

2. The all-solid waste geopolymer grouting material according to claim 1, characterized in that: The mass ratio of the aluminum dihydrogen phosphate, vinyl triacetoxysilane and ethylenediamine-terminated polyethyleneimine is (2-3): (0.5-2):

1.

3. The all-solid waste geopolymer grouting material according to claim 2, characterized in that: The mass ratio of the aluminum dihydrogen phosphate, vinyl triacetoxysilane and ethylenediamine-terminated polyethyleneimine is 2.5:1.5:

1.

4. The all-solid waste geopolymer grouting material according to claim 1, characterized in that: The number average molecular weight of the ethylenediamine-terminated polyethyleneimine is 600-800.

5. The all-solid waste geopolymer grouting material according to claim 1, characterized in that: The raw materials of the all-solid waste mixture include slag powder, steel slag powder, phosphogypsum and fly ash, and the mass ratio of the slag powder, steel slag powder, phosphogypsum and fly ash is (20-50): (25-45): (30-60): (5-30).

6. The all-solid waste geopolymer grouting material according to claim 1, characterized in that: The alkaline activator is at least one of sodium hydroxide, potassium hydroxide, water glass and sodium carbonate.

7. The all-solid waste geopolymer grouting material according to claim 1, characterized in that: The early strength agent is a mixture of sodium thiosulfate and triisopropanolamine in a mass ratio of 1: (0.2-0.5), and the water reducer is a polycarboxylic acid water reducer.

8. A method for preparing a solid waste geopolymer grouting material according to any one of claims 1 to 7, characterized in that: The method comprises the following steps: S1. uniformly mixing slag powder, steel slag powder, phosphogypsum and fly ash to obtain a solid waste mixture; S2. mixing the solid waste mixture, an alkaline activator and 1 / 3 water for activation; S3. adding a certain proportion of an early strength agent, a water reducing agent, a modifier and the remaining water to step S2 and uniformly mixing to obtain a solid waste geopolymer grouting material.

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